Prior art force touch has been applied more and more widely. The earliest force touch technology that came into view of the public is a watch with force touch function. The process thereof is to install a gravity sensing device at four corners of the watch respectively, thereby providing action feedbacks for three dimensions of light click, light press and heavy press. This enables the touch interaction to extend from the “time” dimension of long press to the “force” dimension of heavy press, which develops a brand-new space for the human-machine interaction.
However, the force touch function implemented in the prior art only identifies three kinds of forces, i.e. light, medium and heavy forces. Moreover, it is relatively easy for a small-size watch to realize force sensing, while it is relatively difficult for a large-size display to realize force sensing only by installing gravity sensing devices at four corners.